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Comparing AnyEvent/lib/AnyEvent/Handle.pm (file contents):
Revision 1.32 by root, Sun May 25 01:10:54 2008 UTC vs.
Revision 1.113 by root, Wed Jan 21 06:02:21 2009 UTC

1package AnyEvent::Handle; 1package AnyEvent::Handle;
2 2
3no warnings; 3no warnings;
4use strict; 4use strict qw(subs vars);
5 5
6use AnyEvent (); 6use AnyEvent ();
7use AnyEvent::Util qw(WSAEAGAIN); 7use AnyEvent::Util qw(WSAEWOULDBLOCK);
8use Scalar::Util (); 8use Scalar::Util ();
9use Carp (); 9use Carp ();
10use Fcntl (); 10use Fcntl ();
11use Errno qw/EAGAIN EINTR/; 11use Errno qw(EAGAIN EINTR);
12 12
13=head1 NAME 13=head1 NAME
14 14
15AnyEvent::Handle - non-blocking I/O on file handles via AnyEvent 15AnyEvent::Handle - non-blocking I/O on file handles via AnyEvent
16 16
17=cut 17=cut
18 18
19our $VERSION = '0.04'; 19our $VERSION = 4.331;
20 20
21=head1 SYNOPSIS 21=head1 SYNOPSIS
22 22
23 use AnyEvent; 23 use AnyEvent;
24 use AnyEvent::Handle; 24 use AnyEvent::Handle;
27 27
28 my $handle = 28 my $handle =
29 AnyEvent::Handle->new ( 29 AnyEvent::Handle->new (
30 fh => \*STDIN, 30 fh => \*STDIN,
31 on_eof => sub { 31 on_eof => sub {
32 $cv->broadcast; 32 $cv->send;
33 }, 33 },
34 ); 34 );
35 35
36 # send some request line 36 # send some request line
37 $handle->push_write ("getinfo\015\012"); 37 $handle->push_write ("getinfo\015\012");
49 49
50This module is a helper module to make it easier to do event-based I/O on 50This module is a helper module to make it easier to do event-based I/O on
51filehandles. For utility functions for doing non-blocking connects and accepts 51filehandles. For utility functions for doing non-blocking connects and accepts
52on sockets see L<AnyEvent::Util>. 52on sockets see L<AnyEvent::Util>.
53 53
54The L<AnyEvent::Intro> tutorial contains some well-documented
55AnyEvent::Handle examples.
56
54In the following, when the documentation refers to of "bytes" then this 57In the following, when the documentation refers to of "bytes" then this
55means characters. As sysread and syswrite are used for all I/O, their 58means characters. As sysread and syswrite are used for all I/O, their
56treatment of characters applies to this module as well. 59treatment of characters applies to this module as well.
57 60
58All callbacks will be invoked with the handle object as their first 61All callbacks will be invoked with the handle object as their first
70 73
71=item fh => $filehandle [MANDATORY] 74=item fh => $filehandle [MANDATORY]
72 75
73The filehandle this L<AnyEvent::Handle> object will operate on. 76The filehandle this L<AnyEvent::Handle> object will operate on.
74 77
75NOTE: The filehandle will be set to non-blocking (using 78NOTE: The filehandle will be set to non-blocking mode (using
76AnyEvent::Util::fh_nonblocking). 79C<AnyEvent::Util::fh_nonblocking>) by the constructor and needs to stay in
80that mode.
77 81
78=item on_eof => $cb->($self) 82=item on_eof => $cb->($handle)
79 83
80Set the callback to be called on EOF. 84Set the callback to be called when an end-of-file condition is detected,
85i.e. in the case of a socket, when the other side has closed the
86connection cleanly.
81 87
88For sockets, this just means that the other side has stopped sending data,
89you can still try to write data, and, in fact, one can return from the EOF
90callback and continue writing data, as only the read part has been shut
91down.
92
82While not mandatory, it is highly recommended to set an eof callback, 93While not mandatory, it is I<highly> recommended to set an EOF callback,
83otherwise you might end up with a closed socket while you are still 94otherwise you might end up with a closed socket while you are still
84waiting for data. 95waiting for data.
85 96
97If an EOF condition has been detected but no C<on_eof> callback has been
98set, then a fatal error will be raised with C<$!> set to <0>.
99
86=item on_error => $cb->($self) 100=item on_error => $cb->($handle, $fatal)
87 101
88This is the fatal error callback, that is called when, well, a fatal error 102This is the error callback, which is called when, well, some error
89occurs, such as not being able to resolve the hostname, failure to connect 103occured, such as not being able to resolve the hostname, failure to
90or a read error. 104connect or a read error.
91 105
92The object will not be in a usable state when this callback has been 106Some errors are fatal (which is indicated by C<$fatal> being true). On
93called. 107fatal errors the handle object will be shut down and will not be usable
108(but you are free to look at the current C<< ->rbuf >>). Examples of fatal
109errors are an EOF condition with active (but unsatisifable) read watchers
110(C<EPIPE>) or I/O errors.
111
112Non-fatal errors can be retried by simply returning, but it is recommended
113to simply ignore this parameter and instead abondon the handle object
114when this callback is invoked. Examples of non-fatal errors are timeouts
115C<ETIMEDOUT>) or badly-formatted data (C<EBADMSG>).
94 116
95On callback entrance, the value of C<$!> contains the operating system 117On callback entrance, the value of C<$!> contains the operating system
96error (or C<ENOSPC>, C<EPIPE> or C<EBADMSG>). 118error (or C<ENOSPC>, C<EPIPE>, C<ETIMEDOUT> or C<EBADMSG>).
97 119
98While not mandatory, it is I<highly> recommended to set this callback, as 120While not mandatory, it is I<highly> recommended to set this callback, as
99you will not be notified of errors otherwise. The default simply calls 121you will not be notified of errors otherwise. The default simply calls
100die. 122C<croak>.
101 123
102=item on_read => $cb->($self) 124=item on_read => $cb->($handle)
103 125
104This sets the default read callback, which is called when data arrives 126This sets the default read callback, which is called when data arrives
105and no read request is in the queue. 127and no read request is in the queue (unlike read queue callbacks, this
128callback will only be called when at least one octet of data is in the
129read buffer).
106 130
107To access (and remove data from) the read buffer, use the C<< ->rbuf >> 131To access (and remove data from) the read buffer, use the C<< ->rbuf >>
108method or access the C<$self->{rbuf}> member directly. 132method or access the C<$handle->{rbuf}> member directly.
109 133
110When an EOF condition is detected then AnyEvent::Handle will first try to 134When an EOF condition is detected then AnyEvent::Handle will first try to
111feed all the remaining data to the queued callbacks and C<on_read> before 135feed all the remaining data to the queued callbacks and C<on_read> before
112calling the C<on_eof> callback. If no progress can be made, then a fatal 136calling the C<on_eof> callback. If no progress can be made, then a fatal
113error will be raised (with C<$!> set to C<EPIPE>). 137error will be raised (with C<$!> set to C<EPIPE>).
114 138
115=item on_drain => $cb->() 139=item on_drain => $cb->($handle)
116 140
117This sets the callback that is called when the write buffer becomes empty 141This sets the callback that is called when the write buffer becomes empty
118(or when the callback is set and the buffer is empty already). 142(or when the callback is set and the buffer is empty already).
119 143
120To append to the write buffer, use the C<< ->push_write >> method. 144To append to the write buffer, use the C<< ->push_write >> method.
121 145
146This callback is useful when you don't want to put all of your write data
147into the queue at once, for example, when you want to write the contents
148of some file to the socket you might not want to read the whole file into
149memory and push it into the queue, but instead only read more data from
150the file when the write queue becomes empty.
151
152=item timeout => $fractional_seconds
153
154If non-zero, then this enables an "inactivity" timeout: whenever this many
155seconds pass without a successful read or write on the underlying file
156handle, the C<on_timeout> callback will be invoked (and if that one is
157missing, a non-fatal C<ETIMEDOUT> error will be raised).
158
159Note that timeout processing is also active when you currently do not have
160any outstanding read or write requests: If you plan to keep the connection
161idle then you should disable the timout temporarily or ignore the timeout
162in the C<on_timeout> callback, in which case AnyEvent::Handle will simply
163restart the timeout.
164
165Zero (the default) disables this timeout.
166
167=item on_timeout => $cb->($handle)
168
169Called whenever the inactivity timeout passes. If you return from this
170callback, then the timeout will be reset as if some activity had happened,
171so this condition is not fatal in any way.
172
122=item rbuf_max => <bytes> 173=item rbuf_max => <bytes>
123 174
124If defined, then a fatal error will be raised (with C<$!> set to C<ENOSPC>) 175If defined, then a fatal error will be raised (with C<$!> set to C<ENOSPC>)
125when the read buffer ever (strictly) exceeds this size. This is useful to 176when the read buffer ever (strictly) exceeds this size. This is useful to
126avoid denial-of-service attacks. 177avoid some forms of denial-of-service attacks.
127 178
128For example, a server accepting connections from untrusted sources should 179For example, a server accepting connections from untrusted sources should
129be configured to accept only so-and-so much data that it cannot act on 180be configured to accept only so-and-so much data that it cannot act on
130(for example, when expecting a line, an attacker could send an unlimited 181(for example, when expecting a line, an attacker could send an unlimited
131amount of data without a callback ever being called as long as the line 182amount of data without a callback ever being called as long as the line
132isn't finished). 183isn't finished).
133 184
185=item autocork => <boolean>
186
187When disabled (the default), then C<push_write> will try to immediately
188write the data to the handle, if possible. This avoids having to register
189a write watcher and wait for the next event loop iteration, but can
190be inefficient if you write multiple small chunks (on the wire, this
191disadvantage is usually avoided by your kernel's nagle algorithm, see
192C<no_delay>, but this option can save costly syscalls).
193
194When enabled, then writes will always be queued till the next event loop
195iteration. This is efficient when you do many small writes per iteration,
196but less efficient when you do a single write only per iteration (or when
197the write buffer often is full). It also increases write latency.
198
199=item no_delay => <boolean>
200
201When doing small writes on sockets, your operating system kernel might
202wait a bit for more data before actually sending it out. This is called
203the Nagle algorithm, and usually it is beneficial.
204
205In some situations you want as low a delay as possible, which can be
206accomplishd by setting this option to a true value.
207
208The default is your opertaing system's default behaviour (most likely
209enabled), this option explicitly enables or disables it, if possible.
210
134=item read_size => <bytes> 211=item read_size => <bytes>
135 212
136The default read block size (the amount of bytes this module will try to read 213The default read block size (the amount of bytes this module will
137on each [loop iteration). Default: C<4096>. 214try to read during each loop iteration, which affects memory
215requirements). Default: C<8192>.
138 216
139=item low_water_mark => <bytes> 217=item low_water_mark => <bytes>
140 218
141Sets the amount of bytes (default: C<0>) that make up an "empty" write 219Sets the amount of bytes (default: C<0>) that make up an "empty" write
142buffer: If the write reaches this size or gets even samller it is 220buffer: If the write reaches this size or gets even samller it is
143considered empty. 221considered empty.
144 222
223Sometimes it can be beneficial (for performance reasons) to add data to
224the write buffer before it is fully drained, but this is a rare case, as
225the operating system kernel usually buffers data as well, so the default
226is good in almost all cases.
227
228=item linger => <seconds>
229
230If non-zero (default: C<3600>), then the destructor of the
231AnyEvent::Handle object will check whether there is still outstanding
232write data and will install a watcher that will write this data to the
233socket. No errors will be reported (this mostly matches how the operating
234system treats outstanding data at socket close time).
235
236This will not work for partial TLS data that could not be encoded
237yet. This data will be lost. Calling the C<stoptls> method in time might
238help.
239
145=item tls => "accept" | "connect" | Net::SSLeay::SSL object 240=item tls => "accept" | "connect" | Net::SSLeay::SSL object
146 241
147When this parameter is given, it enables TLS (SSL) mode, that means it 242When this parameter is given, it enables TLS (SSL) mode, that means
148will start making tls handshake and will transparently encrypt/decrypt 243AnyEvent will start a TLS handshake as soon as the conenction has been
149data. 244established and will transparently encrypt/decrypt data afterwards.
150 245
151TLS mode requires Net::SSLeay to be installed (it will be loaded 246TLS mode requires Net::SSLeay to be installed (it will be loaded
152automatically when you try to create a TLS handle). 247automatically when you try to create a TLS handle): this module doesn't
248have a dependency on that module, so if your module requires it, you have
249to add the dependency yourself.
153 250
154For the TLS server side, use C<accept>, and for the TLS client side of a 251Unlike TCP, TLS has a server and client side: for the TLS server side, use
155connection, use C<connect> mode. 252C<accept>, and for the TLS client side of a connection, use C<connect>
253mode.
156 254
157You can also provide your own TLS connection object, but you have 255You can also provide your own TLS connection object, but you have
158to make sure that you call either C<Net::SSLeay::set_connect_state> 256to make sure that you call either C<Net::SSLeay::set_connect_state>
159or C<Net::SSLeay::set_accept_state> on it before you pass it to 257or C<Net::SSLeay::set_accept_state> on it before you pass it to
160AnyEvent::Handle. 258AnyEvent::Handle.
161 259
260B<IMPORTANT:> since Net::SSLeay "objects" are really only integers,
261passing in the wrong integer will lead to certain crash. This most often
262happens when one uses a stylish C<< tls => 1 >> and is surprised about the
263segmentation fault.
264
162See the C<starttls> method if you need to start TLs negotiation later. 265See the C<< ->starttls >> method for when need to start TLS negotiation later.
163 266
164=item tls_ctx => $ssl_ctx 267=item tls_ctx => $ssl_ctx
165 268
166Use the given Net::SSLeay::CTX object to create the new TLS connection 269Use the given C<Net::SSLeay::CTX> object to create the new TLS connection
167(unless a connection object was specified directly). If this parameter is 270(unless a connection object was specified directly). If this parameter is
168missing, then AnyEvent::Handle will use C<AnyEvent::Handle::TLS_CTX>. 271missing, then AnyEvent::Handle will use C<AnyEvent::Handle::TLS_CTX>.
169 272
273=item json => JSON or JSON::XS object
274
275This is the json coder object used by the C<json> read and write types.
276
277If you don't supply it, then AnyEvent::Handle will create and use a
278suitable one (on demand), which will write and expect UTF-8 encoded JSON
279texts.
280
281Note that you are responsible to depend on the JSON module if you want to
282use this functionality, as AnyEvent does not have a dependency itself.
283
170=back 284=back
171 285
172=cut 286=cut
173 287
174sub new { 288sub new {
178 292
179 $self->{fh} or Carp::croak "mandatory argument fh is missing"; 293 $self->{fh} or Carp::croak "mandatory argument fh is missing";
180 294
181 AnyEvent::Util::fh_nonblocking $self->{fh}, 1; 295 AnyEvent::Util::fh_nonblocking $self->{fh}, 1;
182 296
183 if ($self->{tls}) {
184 require Net::SSLeay;
185 $self->starttls (delete $self->{tls}, delete $self->{tls_ctx}); 297 $self->starttls (delete $self->{tls}, delete $self->{tls_ctx})
186 } 298 if $self->{tls};
187 299
188 $self->on_eof (delete $self->{on_eof} ) if $self->{on_eof}; 300 $self->{_activity} = AnyEvent->now;
189 $self->on_error (delete $self->{on_error}) if $self->{on_error}; 301 $self->_timeout;
302
190 $self->on_drain (delete $self->{on_drain}) if $self->{on_drain}; 303 $self->on_drain (delete $self->{on_drain}) if exists $self->{on_drain};
191 $self->on_read (delete $self->{on_read} ) if $self->{on_read}; 304 $self->no_delay (delete $self->{no_delay}) if exists $self->{no_delay};
192 305
193 $self->start_read; 306 $self->start_read
307 if $self->{on_read};
194 308
195 $self 309 $self
196} 310}
197 311
198sub _shutdown { 312sub _shutdown {
199 my ($self) = @_; 313 my ($self) = @_;
200 314
315 delete $self->{_tw};
201 delete $self->{rw}; 316 delete $self->{_rw};
202 delete $self->{ww}; 317 delete $self->{_ww};
203 delete $self->{fh}; 318 delete $self->{fh};
204}
205 319
320 &_freetls;
321
322 delete $self->{on_read};
323 delete $self->{_queue};
324}
325
206sub error { 326sub _error {
207 my ($self) = @_; 327 my ($self, $errno, $fatal) = @_;
208 328
209 {
210 local $!;
211 $self->_shutdown; 329 $self->_shutdown
212 } 330 if $fatal;
331
332 $! = $errno;
213 333
214 if ($self->{on_error}) { 334 if ($self->{on_error}) {
215 $self->{on_error}($self); 335 $self->{on_error}($self, $fatal);
216 } else { 336 } elsif ($self->{fh}) {
217 Carp::croak "AnyEvent::Handle uncaught fatal error: $!"; 337 Carp::croak "AnyEvent::Handle uncaught error: $!";
218 } 338 }
219} 339}
220 340
221=item $fh = $handle->fh 341=item $fh = $handle->fh
222 342
223This method returns the file handle of the L<AnyEvent::Handle> object. 343This method returns the file handle used to create the L<AnyEvent::Handle> object.
224 344
225=cut 345=cut
226 346
227sub fh { $_[0]->{fh} } 347sub fh { $_[0]{fh} }
228 348
229=item $handle->on_error ($cb) 349=item $handle->on_error ($cb)
230 350
231Replace the current C<on_error> callback (see the C<on_error> constructor argument). 351Replace the current C<on_error> callback (see the C<on_error> constructor argument).
232 352
244 364
245sub on_eof { 365sub on_eof {
246 $_[0]{on_eof} = $_[1]; 366 $_[0]{on_eof} = $_[1];
247} 367}
248 368
369=item $handle->on_timeout ($cb)
370
371Replace the current C<on_timeout> callback, or disables the callback (but
372not the timeout) if C<$cb> = C<undef>. See the C<timeout> constructor
373argument and method.
374
375=cut
376
377sub on_timeout {
378 $_[0]{on_timeout} = $_[1];
379}
380
381=item $handle->autocork ($boolean)
382
383Enables or disables the current autocork behaviour (see C<autocork>
384constructor argument). Changes will only take effect on the next write.
385
386=cut
387
388sub autocork {
389 $_[0]{autocork} = $_[1];
390}
391
392=item $handle->no_delay ($boolean)
393
394Enables or disables the C<no_delay> setting (see constructor argument of
395the same name for details).
396
397=cut
398
399sub no_delay {
400 $_[0]{no_delay} = $_[1];
401
402 eval {
403 local $SIG{__DIE__};
404 setsockopt $_[0]{fh}, &Socket::IPPROTO_TCP, &Socket::TCP_NODELAY, int $_[1];
405 };
406}
407
408#############################################################################
409
410=item $handle->timeout ($seconds)
411
412Configures (or disables) the inactivity timeout.
413
414=cut
415
416sub timeout {
417 my ($self, $timeout) = @_;
418
419 $self->{timeout} = $timeout;
420 $self->_timeout;
421}
422
423# reset the timeout watcher, as neccessary
424# also check for time-outs
425sub _timeout {
426 my ($self) = @_;
427
428 if ($self->{timeout}) {
429 my $NOW = AnyEvent->now;
430
431 # when would the timeout trigger?
432 my $after = $self->{_activity} + $self->{timeout} - $NOW;
433
434 # now or in the past already?
435 if ($after <= 0) {
436 $self->{_activity} = $NOW;
437
438 if ($self->{on_timeout}) {
439 $self->{on_timeout}($self);
440 } else {
441 $self->_error (&Errno::ETIMEDOUT);
442 }
443
444 # callback could have changed timeout value, optimise
445 return unless $self->{timeout};
446
447 # calculate new after
448 $after = $self->{timeout};
449 }
450
451 Scalar::Util::weaken $self;
452 return unless $self; # ->error could have destroyed $self
453
454 $self->{_tw} ||= AnyEvent->timer (after => $after, cb => sub {
455 delete $self->{_tw};
456 $self->_timeout;
457 });
458 } else {
459 delete $self->{_tw};
460 }
461}
462
249############################################################################# 463#############################################################################
250 464
251=back 465=back
252 466
253=head2 WRITE QUEUE 467=head2 WRITE QUEUE
274 my ($self, $cb) = @_; 488 my ($self, $cb) = @_;
275 489
276 $self->{on_drain} = $cb; 490 $self->{on_drain} = $cb;
277 491
278 $cb->($self) 492 $cb->($self)
279 if $cb && $self->{low_water_mark} >= length $self->{wbuf}; 493 if $cb && $self->{low_water_mark} >= (length $self->{wbuf}) + (length $self->{_tls_wbuf});
280} 494}
281 495
282=item $handle->push_write ($data) 496=item $handle->push_write ($data)
283 497
284Queues the given scalar to be written. You can push as much data as you 498Queues the given scalar to be written. You can push as much data as you
288=cut 502=cut
289 503
290sub _drain_wbuf { 504sub _drain_wbuf {
291 my ($self) = @_; 505 my ($self) = @_;
292 506
293 if (!$self->{ww} && length $self->{wbuf}) { 507 if (!$self->{_ww} && length $self->{wbuf}) {
508
294 Scalar::Util::weaken $self; 509 Scalar::Util::weaken $self;
510
295 my $cb = sub { 511 my $cb = sub {
296 my $len = syswrite $self->{fh}, $self->{wbuf}; 512 my $len = syswrite $self->{fh}, $self->{wbuf};
297 513
298 if ($len >= 0) { 514 if ($len >= 0) {
299 substr $self->{wbuf}, 0, $len, ""; 515 substr $self->{wbuf}, 0, $len, "";
300 516
517 $self->{_activity} = AnyEvent->now;
518
301 $self->{on_drain}($self) 519 $self->{on_drain}($self)
302 if $self->{low_water_mark} >= length $self->{wbuf} 520 if $self->{low_water_mark} >= (length $self->{wbuf}) + (length $self->{_tls_wbuf})
303 && $self->{on_drain}; 521 && $self->{on_drain};
304 522
305 delete $self->{ww} unless length $self->{wbuf}; 523 delete $self->{_ww} unless length $self->{wbuf};
306 } elsif ($! != EAGAIN && $! != EINTR && $! != WSAEAGAIN) { 524 } elsif ($! != EAGAIN && $! != EINTR && $! != WSAEWOULDBLOCK) {
307 $self->error; 525 $self->_error ($!, 1);
308 } 526 }
309 }; 527 };
310 528
529 # try to write data immediately
530 $cb->() unless $self->{autocork};
531
532 # if still data left in wbuf, we need to poll
311 $self->{ww} = AnyEvent->io (fh => $self->{fh}, poll => "w", cb => $cb); 533 $self->{_ww} = AnyEvent->io (fh => $self->{fh}, poll => "w", cb => $cb)
312 534 if length $self->{wbuf};
313 $cb->($self);
314 }; 535 };
315} 536}
316 537
317our %WH; 538our %WH;
318 539
328 549
329 @_ = ($WH{$type} or Carp::croak "unsupported type passed to AnyEvent::Handle::push_write") 550 @_ = ($WH{$type} or Carp::croak "unsupported type passed to AnyEvent::Handle::push_write")
330 ->($self, @_); 551 ->($self, @_);
331 } 552 }
332 553
333 if ($self->{filter_w}) { 554 if ($self->{tls}) {
334 $self->{filter_w}->($self, \$_[0]); 555 $self->{_tls_wbuf} .= $_[0];
556
557 &_dotls ($self);
335 } else { 558 } else {
336 $self->{wbuf} .= $_[0]; 559 $self->{wbuf} .= $_[0];
337 $self->_drain_wbuf; 560 $self->_drain_wbuf;
338 } 561 }
339} 562}
340 563
341=item $handle->push_write (type => @args) 564=item $handle->push_write (type => @args)
342 565
343=item $handle->unshift_write (type => @args)
344
345Instead of formatting your data yourself, you can also let this module do 566Instead of formatting your data yourself, you can also let this module do
346the job by specifying a type and type-specific arguments. 567the job by specifying a type and type-specific arguments.
347 568
348Predefined types are (if you have ideas for additional types, feel free to 569Predefined types are (if you have ideas for additional types, feel free to
349drop by and tell us): 570drop by and tell us):
353=item netstring => $string 574=item netstring => $string
354 575
355Formats the given value as netstring 576Formats the given value as netstring
356(http://cr.yp.to/proto/netstrings.txt, this is not a recommendation to use them). 577(http://cr.yp.to/proto/netstrings.txt, this is not a recommendation to use them).
357 578
358=back
359
360=cut 579=cut
361 580
362register_write_type netstring => sub { 581register_write_type netstring => sub {
363 my ($self, $string) = @_; 582 my ($self, $string) = @_;
364 583
365 sprintf "%d:%s,", (length $string), $string 584 (length $string) . ":$string,"
366}; 585};
367 586
587=item packstring => $format, $data
588
589An octet string prefixed with an encoded length. The encoding C<$format>
590uses the same format as a Perl C<pack> format, but must specify a single
591integer only (only one of C<cCsSlLqQiInNvVjJw> is allowed, plus an
592optional C<!>, C<< < >> or C<< > >> modifier).
593
594=cut
595
596register_write_type packstring => sub {
597 my ($self, $format, $string) = @_;
598
599 pack "$format/a*", $string
600};
601
602=item json => $array_or_hashref
603
604Encodes the given hash or array reference into a JSON object. Unless you
605provide your own JSON object, this means it will be encoded to JSON text
606in UTF-8.
607
608JSON objects (and arrays) are self-delimiting, so you can write JSON at
609one end of a handle and read them at the other end without using any
610additional framing.
611
612The generated JSON text is guaranteed not to contain any newlines: While
613this module doesn't need delimiters after or between JSON texts to be
614able to read them, many other languages depend on that.
615
616A simple RPC protocol that interoperates easily with others is to send
617JSON arrays (or objects, although arrays are usually the better choice as
618they mimic how function argument passing works) and a newline after each
619JSON text:
620
621 $handle->push_write (json => ["method", "arg1", "arg2"]); # whatever
622 $handle->push_write ("\012");
623
624An AnyEvent::Handle receiver would simply use the C<json> read type and
625rely on the fact that the newline will be skipped as leading whitespace:
626
627 $handle->push_read (json => sub { my $array = $_[1]; ... });
628
629Other languages could read single lines terminated by a newline and pass
630this line into their JSON decoder of choice.
631
632=cut
633
634register_write_type json => sub {
635 my ($self, $ref) = @_;
636
637 require JSON;
638
639 $self->{json} ? $self->{json}->encode ($ref)
640 : JSON::encode_json ($ref)
641};
642
643=item storable => $reference
644
645Freezes the given reference using L<Storable> and writes it to the
646handle. Uses the C<nfreeze> format.
647
648=cut
649
650register_write_type storable => sub {
651 my ($self, $ref) = @_;
652
653 require Storable;
654
655 pack "w/a*", Storable::nfreeze ($ref)
656};
657
658=back
659
368=item AnyEvent::Handle::register_write_type type => $coderef->($self, @args) 660=item AnyEvent::Handle::register_write_type type => $coderef->($handle, @args)
369 661
370This function (not method) lets you add your own types to C<push_write>. 662This function (not method) lets you add your own types to C<push_write>.
371Whenever the given C<type> is used, C<push_write> will invoke the code 663Whenever the given C<type> is used, C<push_write> will invoke the code
372reference with the handle object and the remaining arguments. 664reference with the handle object and the remaining arguments.
373 665
392ways, the "simple" way, using only C<on_read> and the "complex" way, using 684ways, the "simple" way, using only C<on_read> and the "complex" way, using
393a queue. 685a queue.
394 686
395In the simple case, you just install an C<on_read> callback and whenever 687In the simple case, you just install an C<on_read> callback and whenever
396new data arrives, it will be called. You can then remove some data (if 688new data arrives, it will be called. You can then remove some data (if
397enough is there) from the read buffer (C<< $handle->rbuf >>) if you want 689enough is there) from the read buffer (C<< $handle->rbuf >>). Or you cna
398or not. 690leave the data there if you want to accumulate more (e.g. when only a
691partial message has been received so far).
399 692
400In the more complex case, you want to queue multiple callbacks. In this 693In the more complex case, you want to queue multiple callbacks. In this
401case, AnyEvent::Handle will call the first queued callback each time new 694case, AnyEvent::Handle will call the first queued callback each time new
402data arrives and removes it when it has done its job (see C<push_read>, 695data arrives (also the first time it is queued) and removes it when it has
403below). 696done its job (see C<push_read>, below).
404 697
405This way you can, for example, push three line-reads, followed by reading 698This way you can, for example, push three line-reads, followed by reading
406a chunk of data, and AnyEvent::Handle will execute them in order. 699a chunk of data, and AnyEvent::Handle will execute them in order.
407 700
408Example 1: EPP protocol parser. EPP sends 4 byte length info, followed by 701Example 1: EPP protocol parser. EPP sends 4 byte length info, followed by
409the specified number of bytes which give an XML datagram. 702the specified number of bytes which give an XML datagram.
410 703
411 # in the default state, expect some header bytes 704 # in the default state, expect some header bytes
412 $handle->on_read (sub { 705 $handle->on_read (sub {
413 # some data is here, now queue the length-header-read (4 octets) 706 # some data is here, now queue the length-header-read (4 octets)
414 shift->unshift_read_chunk (4, sub { 707 shift->unshift_read (chunk => 4, sub {
415 # header arrived, decode 708 # header arrived, decode
416 my $len = unpack "N", $_[1]; 709 my $len = unpack "N", $_[1];
417 710
418 # now read the payload 711 # now read the payload
419 shift->unshift_read_chunk ($len, sub { 712 shift->unshift_read (chunk => $len, sub {
420 my $xml = $_[1]; 713 my $xml = $_[1];
421 # handle xml 714 # handle xml
422 }); 715 });
423 }); 716 });
424 }); 717 });
425 718
426Example 2: Implement a client for a protocol that replies either with 719Example 2: Implement a client for a protocol that replies either with "OK"
427"OK" and another line or "ERROR" for one request, and 64 bytes for the 720and another line or "ERROR" for the first request that is sent, and 64
428second request. Due tot he availability of a full queue, we can just 721bytes for the second request. Due to the availability of a queue, we can
429pipeline sending both requests and manipulate the queue as necessary in 722just pipeline sending both requests and manipulate the queue as necessary
430the callbacks: 723in the callbacks.
431 724
432 # request one 725When the first callback is called and sees an "OK" response, it will
726C<unshift> another line-read. This line-read will be queued I<before> the
72764-byte chunk callback.
728
729 # request one, returns either "OK + extra line" or "ERROR"
433 $handle->push_write ("request 1\015\012"); 730 $handle->push_write ("request 1\015\012");
434 731
435 # we expect "ERROR" or "OK" as response, so push a line read 732 # we expect "ERROR" or "OK" as response, so push a line read
436 $handle->push_read_line (sub { 733 $handle->push_read (line => sub {
437 # if we got an "OK", we have to _prepend_ another line, 734 # if we got an "OK", we have to _prepend_ another line,
438 # so it will be read before the second request reads its 64 bytes 735 # so it will be read before the second request reads its 64 bytes
439 # which are already in the queue when this callback is called 736 # which are already in the queue when this callback is called
440 # we don't do this in case we got an error 737 # we don't do this in case we got an error
441 if ($_[1] eq "OK") { 738 if ($_[1] eq "OK") {
442 $_[0]->unshift_read_line (sub { 739 $_[0]->unshift_read (line => sub {
443 my $response = $_[1]; 740 my $response = $_[1];
444 ... 741 ...
445 }); 742 });
446 } 743 }
447 }); 744 });
448 745
449 # request two 746 # request two, simply returns 64 octets
450 $handle->push_write ("request 2\015\012"); 747 $handle->push_write ("request 2\015\012");
451 748
452 # simply read 64 bytes, always 749 # simply read 64 bytes, always
453 $handle->push_read_chunk (64, sub { 750 $handle->push_read (chunk => 64, sub {
454 my $response = $_[1]; 751 my $response = $_[1];
455 ... 752 ...
456 }); 753 });
457 754
458=over 4 755=over 4
459 756
460=cut 757=cut
461 758
462sub _drain_rbuf { 759sub _drain_rbuf {
463 my ($self) = @_; 760 my ($self) = @_;
761
762 local $self->{_in_drain} = 1;
464 763
465 if ( 764 if (
466 defined $self->{rbuf_max} 765 defined $self->{rbuf_max}
467 && $self->{rbuf_max} < length $self->{rbuf} 766 && $self->{rbuf_max} < length $self->{rbuf}
468 ) { 767 ) {
469 $! = &Errno::ENOSPC; return $self->error; 768 $self->_error (&Errno::ENOSPC, 1), return;
470 } 769 }
471 770
472 return if $self->{in_drain}; 771 while () {
473 local $self->{in_drain} = 1;
474
475 while (my $len = length $self->{rbuf}) { 772 my $len = length $self->{rbuf};
476 no strict 'refs'; 773
477 if (my $cb = shift @{ $self->{queue} }) { 774 if (my $cb = shift @{ $self->{_queue} }) {
478 unless ($cb->($self)) { 775 unless ($cb->($self)) {
479 if ($self->{eof}) { 776 if ($self->{_eof}) {
480 # no progress can be made (not enough data and no data forthcoming) 777 # no progress can be made (not enough data and no data forthcoming)
481 $! = &Errno::EPIPE; return $self->error; 778 $self->_error (&Errno::EPIPE, 1), return;
482 } 779 }
483 780
484 unshift @{ $self->{queue} }, $cb; 781 unshift @{ $self->{_queue} }, $cb;
485 return; 782 last;
486 } 783 }
487 } elsif ($self->{on_read}) { 784 } elsif ($self->{on_read}) {
785 last unless $len;
786
488 $self->{on_read}($self); 787 $self->{on_read}($self);
489 788
490 if ( 789 if (
491 $self->{eof} # if no further data will arrive
492 && $len == length $self->{rbuf} # and no data has been consumed 790 $len == length $self->{rbuf} # if no data has been consumed
493 && !@{ $self->{queue} } # and the queue is still empty 791 && !@{ $self->{_queue} } # and the queue is still empty
494 && $self->{on_read} # and we still want to read data 792 && $self->{on_read} # but we still have on_read
495 ) { 793 ) {
794 # no further data will arrive
496 # then no progress can be made 795 # so no progress can be made
497 $! = &Errno::EPIPE; return $self->error; 796 $self->_error (&Errno::EPIPE, 1), return
797 if $self->{_eof};
798
799 last; # more data might arrive
498 } 800 }
499 } else { 801 } else {
500 # read side becomes idle 802 # read side becomes idle
501 delete $self->{rw}; 803 delete $self->{_rw} unless $self->{tls};
502 return; 804 last;
503 } 805 }
504 } 806 }
505 807
506 if ($self->{eof}) { 808 if ($self->{_eof}) {
507 $self->_shutdown; 809 if ($self->{on_eof}) {
508 $self->{on_eof}($self) 810 $self->{on_eof}($self)
509 if $self->{on_eof}; 811 } else {
812 $self->_error (0, 1);
813 }
814 }
815
816 # may need to restart read watcher
817 unless ($self->{_rw}) {
818 $self->start_read
819 if $self->{on_read} || @{ $self->{_queue} };
510 } 820 }
511} 821}
512 822
513=item $handle->on_read ($cb) 823=item $handle->on_read ($cb)
514 824
520 830
521sub on_read { 831sub on_read {
522 my ($self, $cb) = @_; 832 my ($self, $cb) = @_;
523 833
524 $self->{on_read} = $cb; 834 $self->{on_read} = $cb;
835 $self->_drain_rbuf if $cb && !$self->{_in_drain};
525} 836}
526 837
527=item $handle->rbuf 838=item $handle->rbuf
528 839
529Returns the read buffer (as a modifiable lvalue). 840Returns the read buffer (as a modifiable lvalue).
577 888
578 $cb = ($RH{$type} or Carp::croak "unsupported type passed to AnyEvent::Handle::push_read") 889 $cb = ($RH{$type} or Carp::croak "unsupported type passed to AnyEvent::Handle::push_read")
579 ->($self, $cb, @_); 890 ->($self, $cb, @_);
580 } 891 }
581 892
582 push @{ $self->{queue} }, $cb; 893 push @{ $self->{_queue} }, $cb;
583 $self->_drain_rbuf; 894 $self->_drain_rbuf unless $self->{_in_drain};
584} 895}
585 896
586sub unshift_read { 897sub unshift_read {
587 my $self = shift; 898 my $self = shift;
588 my $cb = pop; 899 my $cb = pop;
593 $cb = ($RH{$type} or Carp::croak "unsupported type passed to AnyEvent::Handle::unshift_read") 904 $cb = ($RH{$type} or Carp::croak "unsupported type passed to AnyEvent::Handle::unshift_read")
594 ->($self, $cb, @_); 905 ->($self, $cb, @_);
595 } 906 }
596 907
597 908
598 unshift @{ $self->{queue} }, $cb; 909 unshift @{ $self->{_queue} }, $cb;
599 $self->_drain_rbuf; 910 $self->_drain_rbuf unless $self->{_in_drain};
600} 911}
601 912
602=item $handle->push_read (type => @args, $cb) 913=item $handle->push_read (type => @args, $cb)
603 914
604=item $handle->unshift_read (type => @args, $cb) 915=item $handle->unshift_read (type => @args, $cb)
610Predefined types are (if you have ideas for additional types, feel free to 921Predefined types are (if you have ideas for additional types, feel free to
611drop by and tell us): 922drop by and tell us):
612 923
613=over 4 924=over 4
614 925
615=item chunk => $octets, $cb->($self, $data) 926=item chunk => $octets, $cb->($handle, $data)
616 927
617Invoke the callback only once C<$octets> bytes have been read. Pass the 928Invoke the callback only once C<$octets> bytes have been read. Pass the
618data read to the callback. The callback will never be called with less 929data read to the callback. The callback will never be called with less
619data. 930data.
620 931
634 $cb->($_[0], substr $_[0]{rbuf}, 0, $len, ""); 945 $cb->($_[0], substr $_[0]{rbuf}, 0, $len, "");
635 1 946 1
636 } 947 }
637}; 948};
638 949
639# compatibility with older API
640sub push_read_chunk {
641 $_[0]->push_read (chunk => $_[1], $_[2]);
642}
643
644sub unshift_read_chunk {
645 $_[0]->unshift_read (chunk => $_[1], $_[2]);
646}
647
648=item line => [$eol, ]$cb->($self, $line, $eol) 950=item line => [$eol, ]$cb->($handle, $line, $eol)
649 951
650The callback will be called only once a full line (including the end of 952The callback will be called only once a full line (including the end of
651line marker, C<$eol>) has been read. This line (excluding the end of line 953line marker, C<$eol>) has been read. This line (excluding the end of line
652marker) will be passed to the callback as second argument (C<$line>), and 954marker) will be passed to the callback as second argument (C<$line>), and
653the end of line marker as the third argument (C<$eol>). 955the end of line marker as the third argument (C<$eol>).
667=cut 969=cut
668 970
669register_read_type line => sub { 971register_read_type line => sub {
670 my ($self, $cb, $eol) = @_; 972 my ($self, $cb, $eol) = @_;
671 973
672 $eol = qr|(\015?\012)| if @_ < 3; 974 if (@_ < 3) {
975 # this is more than twice as fast as the generic code below
976 sub {
977 $_[0]{rbuf} =~ s/^([^\015\012]*)(\015?\012)// or return;
978
979 $cb->($_[0], $1, $2);
980 1
981 }
982 } else {
673 $eol = quotemeta $eol unless ref $eol; 983 $eol = quotemeta $eol unless ref $eol;
674 $eol = qr|^(.*?)($eol)|s; 984 $eol = qr|^(.*?)($eol)|s;
985
986 sub {
987 $_[0]{rbuf} =~ s/$eol// or return;
988
989 $cb->($_[0], $1, $2);
990 1
991 }
992 }
993};
994
995=item regex => $accept[, $reject[, $skip], $cb->($handle, $data)
996
997Makes a regex match against the regex object C<$accept> and returns
998everything up to and including the match.
999
1000Example: read a single line terminated by '\n'.
1001
1002 $handle->push_read (regex => qr<\n>, sub { ... });
1003
1004If C<$reject> is given and not undef, then it determines when the data is
1005to be rejected: it is matched against the data when the C<$accept> regex
1006does not match and generates an C<EBADMSG> error when it matches. This is
1007useful to quickly reject wrong data (to avoid waiting for a timeout or a
1008receive buffer overflow).
1009
1010Example: expect a single decimal number followed by whitespace, reject
1011anything else (not the use of an anchor).
1012
1013 $handle->push_read (regex => qr<^[0-9]+\s>, qr<[^0-9]>, sub { ... });
1014
1015If C<$skip> is given and not C<undef>, then it will be matched against
1016the receive buffer when neither C<$accept> nor C<$reject> match,
1017and everything preceding and including the match will be accepted
1018unconditionally. This is useful to skip large amounts of data that you
1019know cannot be matched, so that the C<$accept> or C<$reject> regex do not
1020have to start matching from the beginning. This is purely an optimisation
1021and is usually worth only when you expect more than a few kilobytes.
1022
1023Example: expect a http header, which ends at C<\015\012\015\012>. Since we
1024expect the header to be very large (it isn't in practise, but...), we use
1025a skip regex to skip initial portions. The skip regex is tricky in that
1026it only accepts something not ending in either \015 or \012, as these are
1027required for the accept regex.
1028
1029 $handle->push_read (regex =>
1030 qr<\015\012\015\012>,
1031 undef, # no reject
1032 qr<^.*[^\015\012]>,
1033 sub { ... });
1034
1035=cut
1036
1037register_read_type regex => sub {
1038 my ($self, $cb, $accept, $reject, $skip) = @_;
1039
1040 my $data;
1041 my $rbuf = \$self->{rbuf};
675 1042
676 sub { 1043 sub {
677 $_[0]{rbuf} =~ s/$eol// or return; 1044 # accept
678 1045 if ($$rbuf =~ $accept) {
679 $cb->($_[0], $1, $2); 1046 $data .= substr $$rbuf, 0, $+[0], "";
1047 $cb->($self, $data);
1048 return 1;
1049 }
680 1 1050
1051 # reject
1052 if ($reject && $$rbuf =~ $reject) {
1053 $self->_error (&Errno::EBADMSG);
1054 }
1055
1056 # skip
1057 if ($skip && $$rbuf =~ $skip) {
1058 $data .= substr $$rbuf, 0, $+[0], "";
1059 }
1060
1061 ()
681 } 1062 }
682}; 1063};
683 1064
684# compatibility with older API
685sub push_read_line {
686 my $self = shift;
687 $self->push_read (line => @_);
688}
689
690sub unshift_read_line {
691 my $self = shift;
692 $self->unshift_read (line => @_);
693}
694
695=item netstring => $cb->($string) 1065=item netstring => $cb->($handle, $string)
696 1066
697A netstring (http://cr.yp.to/proto/netstrings.txt, this is not an endorsement). 1067A netstring (http://cr.yp.to/proto/netstrings.txt, this is not an endorsement).
698 1068
699Throws an error with C<$!> set to EBADMSG on format violations. 1069Throws an error with C<$!> set to EBADMSG on format violations.
700 1070
704 my ($self, $cb) = @_; 1074 my ($self, $cb) = @_;
705 1075
706 sub { 1076 sub {
707 unless ($_[0]{rbuf} =~ s/^(0|[1-9][0-9]*)://) { 1077 unless ($_[0]{rbuf} =~ s/^(0|[1-9][0-9]*)://) {
708 if ($_[0]{rbuf} =~ /[^0-9]/) { 1078 if ($_[0]{rbuf} =~ /[^0-9]/) {
709 $! = &Errno::EBADMSG; 1079 $self->_error (&Errno::EBADMSG);
710 $self->error;
711 } 1080 }
712 return; 1081 return;
713 } 1082 }
714 1083
715 my $len = $1; 1084 my $len = $1;
718 my $string = $_[1]; 1087 my $string = $_[1];
719 $_[0]->unshift_read (chunk => 1, sub { 1088 $_[0]->unshift_read (chunk => 1, sub {
720 if ($_[1] eq ",") { 1089 if ($_[1] eq ",") {
721 $cb->($_[0], $string); 1090 $cb->($_[0], $string);
722 } else { 1091 } else {
723 $! = &Errno::EBADMSG; 1092 $self->_error (&Errno::EBADMSG);
724 $self->error;
725 } 1093 }
726 }); 1094 });
727 }); 1095 });
728 1096
729 1 1097 1
730 } 1098 }
731}; 1099};
732 1100
1101=item packstring => $format, $cb->($handle, $string)
1102
1103An octet string prefixed with an encoded length. The encoding C<$format>
1104uses the same format as a Perl C<pack> format, but must specify a single
1105integer only (only one of C<cCsSlLqQiInNvVjJw> is allowed, plus an
1106optional C<!>, C<< < >> or C<< > >> modifier).
1107
1108For example, DNS over TCP uses a prefix of C<n> (2 octet network order),
1109EPP uses a prefix of C<N> (4 octtes).
1110
1111Example: read a block of data prefixed by its length in BER-encoded
1112format (very efficient).
1113
1114 $handle->push_read (packstring => "w", sub {
1115 my ($handle, $data) = @_;
1116 });
1117
1118=cut
1119
1120register_read_type packstring => sub {
1121 my ($self, $cb, $format) = @_;
1122
1123 sub {
1124 # when we can use 5.10 we can use ".", but for 5.8 we use the re-pack method
1125 defined (my $len = eval { unpack $format, $_[0]{rbuf} })
1126 or return;
1127
1128 $format = length pack $format, $len;
1129
1130 # bypass unshift if we already have the remaining chunk
1131 if ($format + $len <= length $_[0]{rbuf}) {
1132 my $data = substr $_[0]{rbuf}, $format, $len;
1133 substr $_[0]{rbuf}, 0, $format + $len, "";
1134 $cb->($_[0], $data);
1135 } else {
1136 # remove prefix
1137 substr $_[0]{rbuf}, 0, $format, "";
1138
1139 # read remaining chunk
1140 $_[0]->unshift_read (chunk => $len, $cb);
1141 }
1142
1143 1
1144 }
1145};
1146
1147=item json => $cb->($handle, $hash_or_arrayref)
1148
1149Reads a JSON object or array, decodes it and passes it to the
1150callback. When a parse error occurs, an C<EBADMSG> error will be raised.
1151
1152If a C<json> object was passed to the constructor, then that will be used
1153for the final decode, otherwise it will create a JSON coder expecting UTF-8.
1154
1155This read type uses the incremental parser available with JSON version
11562.09 (and JSON::XS version 2.2) and above. You have to provide a
1157dependency on your own: this module will load the JSON module, but
1158AnyEvent does not depend on it itself.
1159
1160Since JSON texts are fully self-delimiting, the C<json> read and write
1161types are an ideal simple RPC protocol: just exchange JSON datagrams. See
1162the C<json> write type description, above, for an actual example.
1163
1164=cut
1165
1166register_read_type json => sub {
1167 my ($self, $cb) = @_;
1168
1169 require JSON;
1170
1171 my $data;
1172 my $rbuf = \$self->{rbuf};
1173
1174 my $json = $self->{json} ||= JSON->new->utf8;
1175
1176 sub {
1177 my $ref = eval { $json->incr_parse ($self->{rbuf}) };
1178
1179 if ($ref) {
1180 $self->{rbuf} = $json->incr_text;
1181 $json->incr_text = "";
1182 $cb->($self, $ref);
1183
1184 1
1185 } elsif ($@) {
1186 # error case
1187 $json->incr_skip;
1188
1189 $self->{rbuf} = $json->incr_text;
1190 $json->incr_text = "";
1191
1192 $self->_error (&Errno::EBADMSG);
1193 ()
1194
1195 } else {
1196 $self->{rbuf} = "";
1197 ()
1198 }
1199 }
1200};
1201
1202=item storable => $cb->($handle, $ref)
1203
1204Deserialises a L<Storable> frozen representation as written by the
1205C<storable> write type (BER-encoded length prefix followed by nfreeze'd
1206data).
1207
1208Raises C<EBADMSG> error if the data could not be decoded.
1209
1210=cut
1211
1212register_read_type storable => sub {
1213 my ($self, $cb) = @_;
1214
1215 require Storable;
1216
1217 sub {
1218 # when we can use 5.10 we can use ".", but for 5.8 we use the re-pack method
1219 defined (my $len = eval { unpack "w", $_[0]{rbuf} })
1220 or return;
1221
1222 my $format = length pack "w", $len;
1223
1224 # bypass unshift if we already have the remaining chunk
1225 if ($format + $len <= length $_[0]{rbuf}) {
1226 my $data = substr $_[0]{rbuf}, $format, $len;
1227 substr $_[0]{rbuf}, 0, $format + $len, "";
1228 $cb->($_[0], Storable::thaw ($data));
1229 } else {
1230 # remove prefix
1231 substr $_[0]{rbuf}, 0, $format, "";
1232
1233 # read remaining chunk
1234 $_[0]->unshift_read (chunk => $len, sub {
1235 if (my $ref = eval { Storable::thaw ($_[1]) }) {
1236 $cb->($_[0], $ref);
1237 } else {
1238 $self->_error (&Errno::EBADMSG);
1239 }
1240 });
1241 }
1242
1243 1
1244 }
1245};
1246
733=back 1247=back
734 1248
735=item AnyEvent::Handle::register_read_type type => $coderef->($self, $cb, @args) 1249=item AnyEvent::Handle::register_read_type type => $coderef->($handle, $cb, @args)
736 1250
737This function (not method) lets you add your own types to C<push_read>. 1251This function (not method) lets you add your own types to C<push_read>.
738 1252
739Whenever the given C<type> is used, C<push_read> will invoke the code 1253Whenever the given C<type> is used, C<push_read> will invoke the code
740reference with the handle object, the callback and the remaining 1254reference with the handle object, the callback and the remaining
742 1256
743The code reference is supposed to return a callback (usually a closure) 1257The code reference is supposed to return a callback (usually a closure)
744that works as a plain read callback (see C<< ->push_read ($cb) >>). 1258that works as a plain read callback (see C<< ->push_read ($cb) >>).
745 1259
746It should invoke the passed callback when it is done reading (remember to 1260It should invoke the passed callback when it is done reading (remember to
747pass C<$self> as first argument as all other callbacks do that). 1261pass C<$handle> as first argument as all other callbacks do that).
748 1262
749Note that this is a function, and all types registered this way will be 1263Note that this is a function, and all types registered this way will be
750global, so try to use unique names. 1264global, so try to use unique names.
751 1265
752For examples, see the source of this module (F<perldoc -m AnyEvent::Handle>, 1266For examples, see the source of this module (F<perldoc -m AnyEvent::Handle>,
755=item $handle->stop_read 1269=item $handle->stop_read
756 1270
757=item $handle->start_read 1271=item $handle->start_read
758 1272
759In rare cases you actually do not want to read anything from the 1273In rare cases you actually do not want to read anything from the
760socket. In this case you can call C<stop_read>. Neither C<on_read> no 1274socket. In this case you can call C<stop_read>. Neither C<on_read> nor
761any queued callbacks will be executed then. To start reading again, call 1275any queued callbacks will be executed then. To start reading again, call
762C<start_read>. 1276C<start_read>.
763 1277
1278Note that AnyEvent::Handle will automatically C<start_read> for you when
1279you change the C<on_read> callback or push/unshift a read callback, and it
1280will automatically C<stop_read> for you when neither C<on_read> is set nor
1281there are any read requests in the queue.
1282
1283These methods will have no effect when in TLS mode (as TLS doesn't support
1284half-duplex connections).
1285
764=cut 1286=cut
765 1287
766sub stop_read { 1288sub stop_read {
767 my ($self) = @_; 1289 my ($self) = @_;
768 1290
769 delete $self->{rw}; 1291 delete $self->{_rw} unless $self->{tls};
770} 1292}
771 1293
772sub start_read { 1294sub start_read {
773 my ($self) = @_; 1295 my ($self) = @_;
774 1296
775 unless ($self->{rw} || $self->{eof}) { 1297 unless ($self->{_rw} || $self->{_eof}) {
776 Scalar::Util::weaken $self; 1298 Scalar::Util::weaken $self;
777 1299
778 $self->{rw} = AnyEvent->io (fh => $self->{fh}, poll => "r", cb => sub { 1300 $self->{_rw} = AnyEvent->io (fh => $self->{fh}, poll => "r", cb => sub {
779 my $rbuf = $self->{filter_r} ? \my $buf : \$self->{rbuf}; 1301 my $rbuf = \($self->{tls} ? my $buf : $self->{rbuf});
780 my $len = sysread $self->{fh}, $$rbuf, $self->{read_size} || 8192, length $$rbuf; 1302 my $len = sysread $self->{fh}, $$rbuf, $self->{read_size} || 8192, length $$rbuf;
781 1303
782 if ($len > 0) { 1304 if ($len > 0) {
783 $self->{filter_r} 1305 $self->{_activity} = AnyEvent->now;
784 ? $self->{filter_r}->($self, $rbuf) 1306
785 : $self->_drain_rbuf; 1307 if ($self->{tls}) {
1308 Net::SSLeay::BIO_write ($self->{_rbio}, $$rbuf);
1309
1310 &_dotls ($self);
1311 } else {
1312 $self->_drain_rbuf unless $self->{_in_drain};
1313 }
786 1314
787 } elsif (defined $len) { 1315 } elsif (defined $len) {
788 delete $self->{rw}; 1316 delete $self->{_rw};
789 $self->{eof} = 1; 1317 $self->{_eof} = 1;
790 $self->_drain_rbuf; 1318 $self->_drain_rbuf unless $self->{_in_drain};
791 1319
792 } elsif ($! != EAGAIN && $! != EINTR && $! != &AnyEvent::Util::WSAEAGAIN) { 1320 } elsif ($! != EAGAIN && $! != EINTR && $! != WSAEWOULDBLOCK) {
793 return $self->error; 1321 return $self->_error ($!, 1);
794 } 1322 }
795 }); 1323 });
796 } 1324 }
797} 1325}
798 1326
1327# poll the write BIO and send the data if applicable
799sub _dotls { 1328sub _dotls {
800 my ($self) = @_; 1329 my ($self) = @_;
801 1330
1331 my $tmp;
1332
802 if (length $self->{tls_wbuf}) { 1333 if (length $self->{_tls_wbuf}) {
803 while ((my $len = Net::SSLeay::write ($self->{tls}, $self->{tls_wbuf})) > 0) { 1334 while (($tmp = Net::SSLeay::write ($self->{tls}, $self->{_tls_wbuf})) > 0) {
804 substr $self->{tls_wbuf}, 0, $len, ""; 1335 substr $self->{_tls_wbuf}, 0, $tmp, "";
805 } 1336 }
806 } 1337 }
807 1338
808 if (defined (my $buf = Net::SSLeay::BIO_read ($self->{tls_wbio}))) { 1339 while (defined ($tmp = Net::SSLeay::read ($self->{tls}))) {
1340 unless (length $tmp) {
1341 # let's treat SSL-eof as we treat normal EOF
1342 delete $self->{_rw};
1343 $self->{_eof} = 1;
1344 &_freetls;
1345 }
1346
1347 $self->{rbuf} .= $tmp;
1348 $self->_drain_rbuf unless $self->{_in_drain};
1349 $self->{tls} or return; # tls session might have gone away in callback
1350 }
1351
1352 $tmp = Net::SSLeay::get_error ($self->{tls}, -1);
1353
1354 if ($tmp != Net::SSLeay::ERROR_WANT_READ ()) {
1355 if ($tmp == Net::SSLeay::ERROR_SYSCALL ()) {
1356 return $self->_error ($!, 1);
1357 } elsif ($tmp == Net::SSLeay::ERROR_SSL ()) {
1358 return $self->_error (&Errno::EIO, 1);
1359 }
1360
1361 # all other errors are fine for our purposes
1362 }
1363
1364 while (length ($tmp = Net::SSLeay::BIO_read ($self->{_wbio}))) {
809 $self->{wbuf} .= $buf; 1365 $self->{wbuf} .= $tmp;
810 $self->_drain_wbuf; 1366 $self->_drain_wbuf;
811 }
812
813 while (defined (my $buf = Net::SSLeay::read ($self->{tls}))) {
814 $self->{rbuf} .= $buf;
815 $self->_drain_rbuf;
816 }
817
818 my $err = Net::SSLeay::get_error ($self->{tls}, -1);
819
820 if ($err!= Net::SSLeay::ERROR_WANT_READ ()) {
821 if ($err == Net::SSLeay::ERROR_SYSCALL ()) {
822 $self->error;
823 } elsif ($err == Net::SSLeay::ERROR_SSL ()) {
824 $! = &Errno::EIO;
825 $self->error;
826 }
827
828 # all others are fine for our purposes
829 } 1367 }
830} 1368}
831 1369
832=item $handle->starttls ($tls[, $tls_ctx]) 1370=item $handle->starttls ($tls[, $tls_ctx])
833 1371
839C<"connect">, C<"accept"> or an existing Net::SSLeay object). 1377C<"connect">, C<"accept"> or an existing Net::SSLeay object).
840 1378
841The second argument is the optional C<Net::SSLeay::CTX> object that is 1379The second argument is the optional C<Net::SSLeay::CTX> object that is
842used when AnyEvent::Handle has to create its own TLS connection object. 1380used when AnyEvent::Handle has to create its own TLS connection object.
843 1381
844=cut 1382The TLS connection object will end up in C<< $handle->{tls} >> after this
1383call and can be used or changed to your liking. Note that the handshake
1384might have already started when this function returns.
845 1385
846# TODO: maybe document... 1386If it an error to start a TLS handshake more than once per
1387AnyEvent::Handle object (this is due to bugs in OpenSSL).
1388
1389=cut
1390
847sub starttls { 1391sub starttls {
848 my ($self, $ssl, $ctx) = @_; 1392 my ($self, $ssl, $ctx) = @_;
849 1393
850 $self->stoptls; 1394 require Net::SSLeay;
851 1395
1396 Carp::croak "it is an error to call starttls more than once on an AnyEvent::Handle object"
1397 if $self->{tls};
1398
852 if ($ssl eq "accept") { 1399 if ($ssl eq "accept") {
853 $ssl = Net::SSLeay::new ($ctx || TLS_CTX ()); 1400 $ssl = Net::SSLeay::new ($ctx || TLS_CTX ());
854 Net::SSLeay::set_accept_state ($ssl); 1401 Net::SSLeay::set_accept_state ($ssl);
855 } elsif ($ssl eq "connect") { 1402 } elsif ($ssl eq "connect") {
856 $ssl = Net::SSLeay::new ($ctx || TLS_CTX ()); 1403 $ssl = Net::SSLeay::new ($ctx || TLS_CTX ());
862 # basically, this is deep magic (because SSL_read should have the same issues) 1409 # basically, this is deep magic (because SSL_read should have the same issues)
863 # but the openssl maintainers basically said: "trust us, it just works". 1410 # but the openssl maintainers basically said: "trust us, it just works".
864 # (unfortunately, we have to hardcode constants because the abysmally misdesigned 1411 # (unfortunately, we have to hardcode constants because the abysmally misdesigned
865 # and mismaintained ssleay-module doesn't even offer them). 1412 # and mismaintained ssleay-module doesn't even offer them).
866 # http://www.mail-archive.com/openssl-dev@openssl.org/msg22420.html 1413 # http://www.mail-archive.com/openssl-dev@openssl.org/msg22420.html
1414 #
1415 # in short: this is a mess.
1416 #
1417 # note that we do not try to keep the length constant between writes as we are required to do.
1418 # we assume that most (but not all) of this insanity only applies to non-blocking cases,
1419 # and we drive openssl fully in blocking mode here. Or maybe we don't - openssl seems to
1420 # have identity issues in that area.
867 Net::SSLeay::CTX_set_mode ($self->{tls}, 1421 Net::SSLeay::CTX_set_mode ($self->{tls},
868 (eval { Net::SSLeay::MODE_ENABLE_PARTIAL_WRITE () } || 1) 1422 (eval { local $SIG{__DIE__}; Net::SSLeay::MODE_ENABLE_PARTIAL_WRITE () } || 1)
869 | (eval { Net::SSLeay::MODE_ACCEPT_MOVING_WRITE_BUFFER () } || 2)); 1423 | (eval { local $SIG{__DIE__}; Net::SSLeay::MODE_ACCEPT_MOVING_WRITE_BUFFER () } || 2));
870 1424
871 $self->{tls_rbio} = Net::SSLeay::BIO_new (Net::SSLeay::BIO_s_mem ()); 1425 $self->{_rbio} = Net::SSLeay::BIO_new (Net::SSLeay::BIO_s_mem ());
872 $self->{tls_wbio} = Net::SSLeay::BIO_new (Net::SSLeay::BIO_s_mem ()); 1426 $self->{_wbio} = Net::SSLeay::BIO_new (Net::SSLeay::BIO_s_mem ());
873 1427
874 Net::SSLeay::set_bio ($ssl, $self->{tls_rbio}, $self->{tls_wbio}); 1428 Net::SSLeay::set_bio ($ssl, $self->{_rbio}, $self->{_wbio});
875 1429
876 $self->{filter_w} = sub { 1430 &_dotls; # need to trigger the initial handshake
877 $_[0]{tls_wbuf} .= ${$_[1]}; 1431 $self->start_read; # make sure we actually do read
878 &_dotls;
879 };
880 $self->{filter_r} = sub {
881 Net::SSLeay::BIO_write ($_[0]{tls_rbio}, ${$_[1]});
882 &_dotls;
883 };
884} 1432}
885 1433
886=item $handle->stoptls 1434=item $handle->stoptls
887 1435
888Destroys the SSL connection, if any. Partial read or write data will be 1436Shuts down the SSL connection - this makes a proper EOF handshake by
889lost. 1437sending a close notify to the other side, but since OpenSSL doesn't
1438support non-blocking shut downs, it is not possible to re-use the stream
1439afterwards.
890 1440
891=cut 1441=cut
892 1442
893sub stoptls { 1443sub stoptls {
894 my ($self) = @_; 1444 my ($self) = @_;
895 1445
1446 if ($self->{tls}) {
1447 Net::SSLeay::shutdown ($self->{tls});
1448
1449 &_dotls;
1450
1451 # we don't give a shit. no, we do, but we can't. no...
1452 # we, we... have to use openssl :/
1453 &_freetls;
1454 }
1455}
1456
1457sub _freetls {
1458 my ($self) = @_;
1459
1460 return unless $self->{tls};
1461
896 Net::SSLeay::free (delete $self->{tls}) if $self->{tls}; 1462 Net::SSLeay::free (delete $self->{tls});
897 delete $self->{tls_rbio}; 1463
898 delete $self->{tls_wbio}; 1464 delete @$self{qw(_rbio _wbio _tls_wbuf)};
899 delete $self->{tls_wbuf};
900 delete $self->{filter_r};
901 delete $self->{filter_w};
902} 1465}
903 1466
904sub DESTROY { 1467sub DESTROY {
905 my $self = shift; 1468 my $self = shift;
906 1469
907 $self->stoptls; 1470 &_freetls;
1471
1472 my $linger = exists $self->{linger} ? $self->{linger} : 3600;
1473
1474 if ($linger && length $self->{wbuf}) {
1475 my $fh = delete $self->{fh};
1476 my $wbuf = delete $self->{wbuf};
1477
1478 my @linger;
1479
1480 push @linger, AnyEvent->io (fh => $fh, poll => "w", cb => sub {
1481 my $len = syswrite $fh, $wbuf, length $wbuf;
1482
1483 if ($len > 0) {
1484 substr $wbuf, 0, $len, "";
1485 } else {
1486 @linger = (); # end
1487 }
1488 });
1489 push @linger, AnyEvent->timer (after => $linger, cb => sub {
1490 @linger = ();
1491 });
1492 }
1493}
1494
1495=item $handle->destroy
1496
1497Shuts down the handle object as much as possible - this call ensures that
1498no further callbacks will be invoked and resources will be freed as much
1499as possible. You must not call any methods on the object afterwards.
1500
1501Normally, you can just "forget" any references to an AnyEvent::Handle
1502object and it will simply shut down. This works in fatal error and EOF
1503callbacks, as well as code outside. It does I<NOT> work in a read or write
1504callback, so when you want to destroy the AnyEvent::Handle object from
1505within such an callback. You I<MUST> call C<< ->destroy >> explicitly in
1506that case.
1507
1508The handle might still linger in the background and write out remaining
1509data, as specified by the C<linger> option, however.
1510
1511=cut
1512
1513sub destroy {
1514 my ($self) = @_;
1515
1516 $self->DESTROY;
1517 %$self = ();
908} 1518}
909 1519
910=item AnyEvent::Handle::TLS_CTX 1520=item AnyEvent::Handle::TLS_CTX
911 1521
912This function creates and returns the Net::SSLeay::CTX object used by 1522This function creates and returns the Net::SSLeay::CTX object used by
942 } 1552 }
943} 1553}
944 1554
945=back 1555=back
946 1556
1557
1558=head1 NONFREQUENTLY ASKED QUESTIONS
1559
1560=over 4
1561
1562=item I C<undef> the AnyEvent::Handle reference inside my callback and
1563still get further invocations!
1564
1565That's because AnyEvent::Handle keeps a reference to itself when handling
1566read or write callbacks.
1567
1568It is only safe to "forget" the reference inside EOF or error callbacks,
1569from within all other callbacks, you need to explicitly call the C<<
1570->destroy >> method.
1571
1572=item I get different callback invocations in TLS mode/Why can't I pause
1573reading?
1574
1575Unlike, say, TCP, TLS connections do not consist of two independent
1576communication channels, one for each direction. Or put differently. The
1577read and write directions are not independent of each other: you cannot
1578write data unless you are also prepared to read, and vice versa.
1579
1580This can mean than, in TLS mode, you might get C<on_error> or C<on_eof>
1581callback invocations when you are not expecting any read data - the reason
1582is that AnyEvent::Handle always reads in TLS mode.
1583
1584During the connection, you have to make sure that you always have a
1585non-empty read-queue, or an C<on_read> watcher. At the end of the
1586connection (or when you no longer want to use it) you can call the
1587C<destroy> method.
1588
1589=item How do I read data until the other side closes the connection?
1590
1591If you just want to read your data into a perl scalar, the easiest way
1592to achieve this is by setting an C<on_read> callback that does nothing,
1593clearing the C<on_eof> callback and in the C<on_error> callback, the data
1594will be in C<$_[0]{rbuf}>:
1595
1596 $handle->on_read (sub { });
1597 $handle->on_eof (undef);
1598 $handle->on_error (sub {
1599 my $data = delete $_[0]{rbuf};
1600 undef $handle;
1601 });
1602
1603The reason to use C<on_error> is that TCP connections, due to latencies
1604and packets loss, might get closed quite violently with an error, when in
1605fact, all data has been received.
1606
1607It is usually better to use acknowledgements when transferring data,
1608to make sure the other side hasn't just died and you got the data
1609intact. This is also one reason why so many internet protocols have an
1610explicit QUIT command.
1611
1612=item I don't want to destroy the handle too early - how do I wait until
1613all data has been written?
1614
1615After writing your last bits of data, set the C<on_drain> callback
1616and destroy the handle in there - with the default setting of
1617C<low_water_mark> this will be called precisely when all data has been
1618written to the socket:
1619
1620 $handle->push_write (...);
1621 $handle->on_drain (sub {
1622 warn "all data submitted to the kernel\n";
1623 undef $handle;
1624 });
1625
1626=back
1627
1628
1629=head1 SUBCLASSING AnyEvent::Handle
1630
1631In many cases, you might want to subclass AnyEvent::Handle.
1632
1633To make this easier, a given version of AnyEvent::Handle uses these
1634conventions:
1635
1636=over 4
1637
1638=item * all constructor arguments become object members.
1639
1640At least initially, when you pass a C<tls>-argument to the constructor it
1641will end up in C<< $handle->{tls} >>. Those members might be changed or
1642mutated later on (for example C<tls> will hold the TLS connection object).
1643
1644=item * other object member names are prefixed with an C<_>.
1645
1646All object members not explicitly documented (internal use) are prefixed
1647with an underscore character, so the remaining non-C<_>-namespace is free
1648for use for subclasses.
1649
1650=item * all members not documented here and not prefixed with an underscore
1651are free to use in subclasses.
1652
1653Of course, new versions of AnyEvent::Handle may introduce more "public"
1654member variables, but thats just life, at least it is documented.
1655
1656=back
1657
947=head1 AUTHOR 1658=head1 AUTHOR
948 1659
949Robin Redeker C<< <elmex at ta-sa.org> >>, Marc Lehmann <schmorp@schmorp.de>. 1660Robin Redeker C<< <elmex at ta-sa.org> >>, Marc Lehmann <schmorp@schmorp.de>.
950 1661
951=cut 1662=cut

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